Imprint apparatus, imprint method, and method of manufacturing article

ABSTRACT

An imprint apparatus that forms a pattern on a substrate by using a mold, the apparatus comprises a supply unit configured to supply an imprint material to the substrate; a contact unit configured to contact the imprint material that has been supplied to the substrate with a mold; a substrate stage configured to move the substrate; a gas supply unit that is provided between the supply unit and the contact unit, and supply gas toward the substrate; and a flow volume adjustment unit configured to adjust a flow volume of the gas that is supplied from the gas supply unit, while the substrate stage moves the substrate from a supply position at which the imprint material is supplied by the supply unit to a contact position at which the imprint material is contacted with the mold by the contact unit.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an imprint apparatus, an imprintmethod, and a method of manufacturing an article.

Description of the Related Art

There is a fine processing technique that contacts a mold with animprint material on a substrate and performs pattern formation. Thistechnique is also referred to as “imprint technique”, and enablesforming a pattern of a few nm order on the substrate. A light curingmethod is an example of the imprint technique. An imprint apparatususing this method forms a pattern on a substrate by applying a photocuring resin (imprint material) to a shot (imprint region) on thesubstrate, contacting the mold with the imprint material (moldpressing), curing the imprint material, and peeling away the mold (moldreleasing). In mold pressing, if particles adhere to the imprintmaterial or the mold, a pattern defect may occur or the mold may bedamaged. Additionally, a pattern defect may occur due to the mixture ofair (residual gas) between the imprint material and the mold in theimprint material that has not been cured as bubbles.

For this drawback related to the adhesion of particles, Japanese PatentApplication Laid-Open Publication No. 59-75626 discloses a patternforming apparatus in which an area around a head holding a mold issurrounded by an air flow to avoid the entry of particles into the areaaround the head. For the drawback related to the residual gas, animprint apparatus in which the residual gas is reduced by usingpermeable gas in an imprint atmosphere (Japanese Patent ApplicationLaid-Open Publication No. 2007-509769), and an imprint apparatus inwhich condensable gas that is liquefied during the pressing of the moldand the volume thereof becomes reduced to a negligible extent is used(Japanese Patent Application Laid-Open Publication No. 2004-103817) aredisclosed.

However, when the technique of Japanese Patent Application Laid-OpenPublication No. 59-75626 is applied to the imprint apparatus, a drop isvolatilized/dried due to the air flow hitting the imprint material(drop) that has not been cured, and the shape may change. Here,volatilized/dried means at least any one of volatilized and dried,volatilized, or dried. Moreover, in the case in which the techniquesdisclosed in Japanese Patent Application Laid-Open Publication No.2007-509769 and Japanese Patent Application Laid-Open Publication No.2004-103817 are also used together, if the air flow is mixed withpermeable gas and condensable gas, the residual gas might notsufficiently be removed. Both could be a cause of occurrence of patterndefects.

SUMMARY OF THE INVENTION

The present invention provides, for example, an imprint apparatus thatis advantageous in reducing pattern defects.

The present invention is an imprint apparatus that forms a pattern on asubstrate by using a mold, the apparatus comprises a supply unitconfigured to supply an imprint material to the substrate; a contactunit configured to contact the imprint material that has been suppliedto the substrate with a mold; a substrate stage configured to move thesubstrate; a gas supply unit that is provided between the supply unitand the contact unit, and configured to supply gas toward the substrate;and a flow volume adjustment unit that is configured to adjust a flowvolume of the gas that is supplied from the gas supply unit, while thesubstrate stage moves the substrate from a supply position at which theimprint material is supplied by the supply unit to a contact position atwhich the imprint material is contacted with the mold by the contactunit.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a configuration of an imprintapparatus according to a first embodiment.

FIG. 2 illustrates a conventional imprint process.

FIG. 3 illustrates a conventional imprint process.

FIG. 4 illustrates an imprint process according to the first embodiment.

FIG. 5 is a flowchart of the imprint process according to the firstembodiment and a second embodiment.

FIG. 6 illustrates an imprint process according to the secondembodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a description will be given of embodiments of the presentinvention with reference to the accompanying drawings and the like.

First Embodiment

FIG. 1 is a schematic diagram illustrating a configuration of an imprintapparatus according to a first embodiment of the present invention.Here, as an imprint apparatus using a photo curing method, anultraviolet rays curing imprint apparatus that cures an uncured resin(imprint material) on a substrate by irradiation of ultraviolet rays isused. However, as a curing method for imprint materials, a method usingirradiation of lights in other wavelength ranges, or a method usingother energies (for example, heat) may be used. An imprint apparatus 100has a mold press unit (mold holding unit, contact unit) 12 that pressesa mold 11 having a pattern surface to the imprint material (contacts themold with the imprint material), a substrate stage (substrate holdingunit) 14, a light source 16, an illumination optical system 17, anapplication unit (dispenser, supply unit) 20, and a control unit 50.

The mold press unit 12 is supported by being attached to a structure 18and movable by a drive source (not illustrated) and the control unit 50.When the mold 11 makes contact with a resin 21 that has been appliedonto a substrate 13 by the application unit 20 (mold pressing), the moldpress unit 12 moves such that the mold 11 approaches the substrate 13.Additionally, when the mold is peeled away (mold releasing), the moldpress unit 12 moves such that the mold 11 is away from the substrate 13.

The substrate stage 14 is movable on a base 19 between a position facingthe application unit 20 (application position) and a position facing themold press unit 12 (mold 11) (contact position) by the drive source (notillustrated) and the control unit 50. The control unit 50 measures theposition of the substrate stage 14 by a detection unit 15, and performspositioning control of the substrate stage 14 with an accuracy of a fewnm or less by a control mechanism (not illustrated) and an alignmentmechanism (not illustrated). As the detection unit 15, a laserinterferometer or an encoder can be used.

The light source 16 and the illumination optical system 17 irradiateultraviolet rays that cure the resin 21. The application unit 20 has anozzle (supply opening) that discharges the resin 21. The control unit50 controls the mold press unit 12, the substrate stage 14, the lightsource 16, and the application unit 20 in a series of the imprintprocesses including the application of the resin, the pressing of themold, the curing of the resin, and the release of the mold.

Moreover, the imprint apparatus 100 includes a first gas filling unit 22and a second gas flow forming unit (second gas supply unit) 24 thatserve as a gas supply means. The first gas filling unit 22 is located soas to surround the mold 11 and be held by the mold press unit 12. Thefirst gas filling unit 22 fills a first gas 23 into the space betweenthe resin 21 and the mold 11 and removes residual gas. The filling ofthe first gas 23 is performed before and after the pressing of the mold,such that the residual gas has been removed during the pressing of themold. That is, during the application of the resin and the like, thefilling of the first gas 23 is not necessary. The first gas 23 includesat least one of a permeable gas and a condensable gas. The permeable gasis dissolved or diffused in at least one of the mold 11, the resin 21,and the substrate 13. Specifically, gases such as helium or hydrogen canbe adopted. However, if combustible hydrogen is used, it is necessary toseparately dispose an explosion-proof system in the imprint apparatus,which has a configuration that considers fire safety. The condensablegas liquefies with the increase of pressure due to mold pressing, andthe volume is reduced to several hundredths as compared with that beforethe liquefaction of the gas. Specifically, hydrofluorocarbon typified bypentafluoropropane can be adopted. Hydrofluoroether can also be used.

The second gas flow forming unit 24 is located between the applicationunit 20 and the mold press unit 12 so as to surround the first gasfilling unit 22 (mold press unit 12) and is held by the structure 18.The second gas flow forming unit 24 supplies a second gas 25, forms anair flow (gas flow) that surrounds the first gas filling unit 22 (moldpress unit 12), and suppresses the enter of particles. Accordingly, theneed to reduce the amount of particles in the entire area of the insideof the imprint apparatus 100 is eliminated, and a space for an airconditioning system of the imprint apparatus 100 can be saved. This gasflow is also referred to as an “air curtain”. The second gas 25 issupplied at all times basically in order to suppress the entry ofparticles. Any gas may be used as the second gas 25, as long as it has asmall number of particles, for example, clean dry air. Additionally, asnecessary, clean dry air that has been passed through a particle removalfilter may also be used.

Note that, inside of the imprint apparatus 100, for example, a ULPAfilter having a particle removal function is passed through, gas thathas been cleaned is blown with a fan, thereby to reduce the particleconcentration. However, even by this process, there is a case in whichparticles adhered to the substrate 13 that is being conveyed enters theimprint apparatus, or dust occurs from a drive unit provided in theimprint apparatus. The formation of the gas flow described above alsoallows suppressing the influence of such particles.

Subsequently, a description will be given of volatilization/drying ofthe resin 21 by the air curtain. FIG. 2 is a schematic diagramillustrating a process in which the resin (drop) 21 that has not beencured is applied onto an imprint region (shot) 26 on the substrate 13 bythe application unit 20, and the substrate 13 is moved so as to be rightunder the mold 11 (mold press position), seen from the side of theimprint apparatus 100. FIG. 3 illustrates the process shown in FIG. 2seen from above. As shown in FIG. 2 and FIG. 3, the second gas flowforming unit 24 is located between the mold press unit 12 and theapplication unit 20. In this case, while the substrate 13 moves from theapplication position to the mold press position, the resin 21 on theshot 26 passes directly under the second gas flow forming unit 24.During the passage, the second gas 25 is blown over the resin 21, theresin 21 is volatized/dried, and the shape changes. As a countermeasureto the shape change, although there is a method in which the amount ofthe resin to be volatized/dried has been taken into account in advanceand the application is performed, this method needs to estimate theamount of change in advance, the working process increases, and therebyto lower the throughput.

Accordingly, in the present embodiment, when the resin 21 that has beenapplied onto the shot 26 on the substrate 13 passes under the second gasflow forming unit 24, the control unit (flow volume adjustment unit) 50performs adjustments such as the reduction of a supply quantity or aflow rate of the second gas 25 and the stopping of the supply of thesecond gas 25. FIG. 4 illustrates the imprint process, seen from above,and a broken line part of the second gas flow forming unit 24 representsthat the reducing of the supply quantity and the flow rate of the secondgas 25 and the stopping of the supply of the second gas 25 is performed.The flow volume when the substrate 13 passes under the second gas flowforming unit 24 is smaller than that when the substrate 13 is in theapplication position or in the mold press position. Thus, the flowvolume of the gas that is supplied from the second gas flow forming unit24 is adjusted, the blowing of the second gas 25 to the resin 21 thathas not been cured is reduced, and as a result, the change of the dropshape due to the volatilization/drying is suppressed. Additionally, theadjustment of flow volume of this gas enables suppressing the mixture ofthe second gas 25 with the first gas 23. These lead to reduction inpattern defects.

FIG. 5 is a flowchart of an imprint process in the present embodiment.In S1, the application unit 20 applies the resin 21 onto the shot 26 onthe substrate 13 (application process). Subsequently, in S3, themovement of the substrate 13 to the mold press position starts (movingprocess). At that time, in S2, the control unit (flow volume adjustmentunit) 50 performs the reduction of the supply quantity and the flow rateof the second gas 25 and the stopping of the supply of the second gas 25by the second gas flow forming unit 24. Thus, the shape change of thedrop due to the volatilization/drying of the resin 21 that has not beencured is suppressed, thereby enabling a reduction in the patterndefects. Note that S2 may be performed during S1. In S3, the substrate13 passes directly under the second gas flow forming unit 24, and in S4,the supply quantity of the second gas 25 is returned to the originalquantity. Subsequently, the substrate 13 completes the movement to themold press position, and mold pressing (S5), exposure (S6), and moldreleasing (S7) are performed. Finally, in S8, it is determined whetheror not all shots have been completed, and if completed (Yes), theimprint process finishes. If all shots have not been completed (No), theimprint process continues from S1 again.

As described above, according to the present embodiment, an imprintapparatus that is advantageous in reducing pattern defects can beprovided.

Second Embodiment

Next, a description will be given of the imprint apparatus 100 accordingto a second embodiment of the present invention. The second gas flowforming unit 24 according to the present embodiment, as shown in FIG. 6,consists of a first forming unit 24-1 and a second forming unit 24-2,and can change the supply quantity and the flow rate of the second gas25 at each forming unit. Specifically, when the resin 21 that is appliedonto the shot 26 on the substrate 13 passes under the second gas flowforming unit 24, the supply quantity and the flow rate of the second gas25 supplied from the second forming unit 24-2 are reduced, and thesupply of the second gas 25 is stopped. In contrast, it is not necessaryto change the supply quantity and the flow rate of the second gas 25supplied from the first forming unit 24-1. Note that the second gas flowforming unit 24 may be divided so as to have two or more gas supplyunits (a plurality of supply units) as in the present embodiment.

Additionally, as shown in the enlarged view in FIG. 6, if the nozzlewidth of the application unit 20 is defined as “a” and the width of thesecond forming unit 24-2 is defined as “b”, a<b is established. That isthe area of the second forming unit 24-2 is equal to or larger than thatof the nozzle width of the application unit 20. Here, “a” may be thewidth of the resin that has actually been applied. Additionally, thesecond forming unit 24-2 is provided nearer to the application positionthan is the first forming unit 24-1. Accordingly, when the resin 21 thathas not been cured passes under the second gas flow forming unit 24, itis possible to reduce the supply quantity and the flow rate of thesecond gas to be blown to the resin 21 that has not been cured or it ispossible to stop the supply the second gas. The broken line part of thesecond forming unit 24-2 represents that the adjustment of the secondgas has been performed. Thus, the shape change of the drop due to thevolatilization/drying of the resin 21 that has not been cured issuppressed, and pattern defects can be reduced. Adjustment of the supplyquantity of the second gas and the like may be carried out in a mannersimilar to the first embodiment. As described above, also by thisembodiment, it is possible to provide an imprint apparatus that isadvantageous in reducing pattern defects.

(Article Manufacturing Method)

A method of manufacturing article such as the aforementioned device (eg,a microchip, a liquid crystal display) according to an embodiment of thepresent invention may include a step of forming a pattern on an object(eg, wafer, glass plate, film substrate) using the aforementionedimprint apparatus. Furthermore, the article manufacturing method mayinclude etching. When other articles such as a patterned medium (storagemedium), an optical element, or the like are manufactured, themanufacturing method may include another step of processing thesubstrate on which a pattern has been formed instead of the etchingstep. The article manufacturing method of this embodiment has anadvantage, as compared with a conventional article manufacturing method,in at least one of performance, quality, productivity and productioncost of a device.

In the above embodiments, although a direction in which gas is suppliedby the second gas supply unit serves as a direction in which gas isblown over the substrate, the present invention is not limited thereby.Additionally, the shape of the gas supply unit is also not limited tothat of the nozzle.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2015-081355 filed Apr. 13, 2015, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An imprint apparatus that forms a pattern on asubstrate by using a mold, the apparatus comprising: an imprint materialsupply unit configured to supply an imprint material to the substrate; amold holding unit configured to hold the mold that contacts the imprintmaterial that has been supplied to the substrate; a substrate stageconfigured to move the substrate between an imprint material supplyposition facing the imprint material supply unit and a contact positionfacing the mold held by the mold holding unit; a gas supply unitconfigured to blow out gas to form an air curtain, wherein the gassupply unit is provided so as to surround the mold when the imprintapparatus is viewed from above so that at least a part of the gas supplyunit is located between the imprint material supply unit and the mold;and a gas flow rate adjustment unit including a control unit configuredto adjust a flow rate of the gas blown out from the gas supply unit,wherein the control unit of the gas flow rate adjustment unit isconfigured to adjust the flow rate of the gas blown out from said atleast a part of the gas supply unit such that the flow rate when thesubstrate to which the imprint material has been supplied passesdirectly under the gas supply unit is smaller than the flow rate whenthe substrate on the substrate stage is located in the contact positionfacing the mold held by the mold holding unit.
 2. The imprint apparatusaccording to claim 1, wherein the control unit of the gas flow rateadjustment unit is further configured to adjust the flow rate of the gasblown out from at least the part of the gas supply unit such that theflow rate when the substrate to which the imprint material has beensupplied passes directly under the gas supply unit is smaller than theflow rate when the substrate on the substrate stage is located in theimprint material supply position facing the imprint material supplyunit.
 3. The imprint apparatus according to claim 1, further including agas filling unit configured to fill gas into the space between the moldand the imprint material where the mold and the substrate are broughtinto contact with each other, wherein the gas filling unit is arrangedinside the gas supply unit so as to surround the mold when the imprintapparatus is viewed from above, and held by the mold holding unit. 4.The imprint apparatus according to claim 1, wherein the gas supply unitis divided into a plurality of gas supply units, and wherein the gasflow volume rate adjustment unit is configured to adjust the flow rateof the gas that is supplied by each gas supply unit of the plurality ofgas supply units.
 5. The imprint apparatus according to claim 4,wherein, among the plurality of gas supply units, the width of the gassupply unit that is located near the imprint material supply position islarger than that of a supply opening for the imprint material at theimprint material supply unit.
 6. The imprint apparatus according toclaim 4, wherein, among the plurality of gas supply units, the width ofthe gas supply unit that is located near the imprint material supplyposition is larger than that of the imprint material that has beensupplied to the substrate.
 7. The imprint apparatus according to claim1, wherein the gas from the gas supply unit is clean dry air.
 8. Theimprint apparatus according to claim 3, wherein gas that is filled bythe gas filling unit includes at least one of permeable gas andcondensable gas.
 9. The imprint apparatus according to claim 1, whereinthe gas flow rate adjustment unit is configured to reduce the flow rateof gas or stop the flow of gas to suppress at least one ofvolatilization, drying, and shape change of the imprint material by thegas supplied by the gas supply unit.
 10. The imprint apparatus accordingto claim 1, wherein the gas supply unit supplies gas flow in a directionfrom the mold holding unit to the substrate.
 11. The imprint apparatusaccording to claim 3, wherein at least a part of the gas filling unit islocated between the part of the gas supply unit and the mold when theimprint apparatus is viewed from above.
 12. The imprint apparatusaccording to claim 4, wherein the control unit of the gas flow rateadjustment unit is further configured to adjust the flow rate of the gasblown from at least one of a plurality of the gas supply units locatedbetween the imprint material supply unit and the mold when the imprintapparatus is viewed from above, and not to adjust the flow rate of thegas blown out from the other of the plurality of the gas supply units,such that the flow rate when the substrate to which the imprint materialhas been supplied passes directly under the at least one of a pluralityof the gas supply unit is smaller than the flow rate when the substrateon the substrate stage is located in the contact position facing themold held by the mold holding unit.